Technical Field
This disclosure relates to a sheet conveying device, an image reading device incorporating the sheet conveying device, and an image forming apparatus incorporating the sheet conveying device.
Related Art
Known various types of image forming apparatuses such as copiers, printer, and facsimile machines and image reading devices include a sheet conveying device to convey a sheet such as a recording medium to an image forming device or a sheet such as an original document to an image reading device.
For example, a known sheet conveying device includes a sound absorber having a configuration of a Helmholtz resonator including a hollow portion and a communication portion to cause the hollow portion to communicate with an outside of the sheet conveying device. The sound absorber is disposed in a sheet conveying passage in the sheet conveying device.
Sliding sound is generated when a conveyance passage forming device such as a guide member to form a sheet conveying passage and a sheet that is being conveyed through the sheet conveying passage. Leakage of the sliding sound to the outside of the sheet conveying device can be restrained by disposing the above-described sound absorber in the sheet conveying passage.
When sheets having paper types different from each other are conveyed, if property values such as the thickness and weight of each sheet to be conveyed change, the attitude of each sheet changes in the sheet conveying passage due to various property values such as the thickness and weight of respective sheets different from each other. Therefore, when a position at which the sheet slides in the conveyance passage forming device changes, a sound occurring position of the sliding sound also changes.
In the sound absorber having the configuration of a Helmholtz resonator, as the communication portion to cause the hollow portion to communicate with the outside of the sheet conveying device is disposed closer to a sound source, the sound absorbing efficiency increases. The sound occurs not only when a sound absorbing target is a sliding sound generated by changing the sound occurring position due to the change of the property value of the sheet but also when a sound absorbing target is a sound generated while the sheet is being conveyed and occurred at the sound occurring position changing in the sheet conveying passage.